c# - Writing to DB using EF6 in async process randomly yielding "property 'Id' is part of object's key ..." -

i have base class called servicepluginbase implements logging.

public class pluginlog  {     public int id { get; set; }     public int? serviceid { get; set; }     public string event { get; set; }     public string details { get; set; }     public datetime datetime { get; set; }     public string user { get; set; } }  public class sqlpluginlogger : ipluginlogger {     //efloggincontext maps pluginlog so:     // modelbuilder.entity<pluginlog>().totable("log").haskey(l => l.id)     private efloggingcontext _logger = new efloggingcontext();      public iqueryable<pluginlog> logitems      {        { return _logger.logitems; }     }      public void logevent(pluginlog item)     {         _logger.logitems.add(item);         _logger.savechanges();     } }  public abstract class servicepluginbase : iplugin {    private ipluginlogger _logger;     public servicepluginbase(ipluginlogger logger)    {        _logger = logger;    }     protected logevent(string eventname, string details)    {        pluginlog _event = new pluginlog()        {            serviceid = this.id,            event = eventname,            details = details,            user = thread.currentprincipal.identity.name,            datetime = datetime.now         };         _logger.logevent(_event);     } } 

now, within concrete class, log events happen. in 1 class, have asynchronous methods running -- , logging. works great. other times, i error stating "property 'id' part of object's key , cannot updated." interestingly enough, have absolutely no code updates value of id , never updates of log entries -- add new ones.

here async code 1 of plugins.

public class cptmanager : servicepluginbase {     public override async task handlepluginprocessasync()     {         ...         await processusersasync(requireduserslist, currentuserslist);     }      private async task processusersasync(list<extendeduser> required, list<extendeduser> current)     {         using (var http = new httpclient())         {             var removals = currentusers.where(cu => !required.select(r => r.id).contains(cu.id)).tolist();             await disableusersasync(removals http);              await addrequiredusersasync(requiredusers.where(ru => ru.mustadd).tolist());         }     }      private async task disableusersasync(list<extendeduser> users, httpclient client)     {         logevent("disable users","total disable: " + users.count());         await task.whenall(users.select(async user =>          {            ...  //http call disable user via web api            string status = "disable user";            if(response.status == "error")            {                emailfaildisablenotification(user);                status += " - fail";            }            logevent(statustext, ...);             if(response.status != "error")            {               //update foxpro database via oledbconnection (not ef)               logevent("clearudf", ...);            }          }));     }      private async task addrequiredusersasync(list<extendeduser> users, httpclient client)     {         logevent("add required users", "total users add: " + users.count());         await task.whenall(users.select(async user =>         {             ...  //http call add user via web api             logevent("add user", ...);              if(response.status != "error")             {                  //update foxpro db via oledbconnection (not ef)                  logevent("udf update",...);             }         }));      } } 

first, i'm confused why i'm getting error mentioned above -- "id can't updated" ... i'm not populating id field nor doing updates log file. there no related tables -- single log table.

my guess i'm doing improperly in regards asynchronous processing, i'm having trouble seeing if am.

any ideas may going on?